Jittered is a term commonly used to describe a feeling of nervousness or anxiety. Other synonyms that can be used in place of jittered include fidgeted, quivered, trembled, shook, or shuddered. These words convey a similar sense of uneasiness or restlessness, often brought about by worry or stress. Additionally, words like agitated, uneasy, or nervous can also be used when describing a feeling of jitteredness. Using synonyms can add depth and variety to your writing, allowing you to more accurately convey the connotations and emotions you wish to express.